Seegee:
I actually thought the opposite, there were many times when CP could have been used, but wasn't. Hermione in particular when she walked out quite rudely on Trelawney's Divination class. Filch is a nutbar, he also wanted to bring back hanging the kids by their thumbs, he seems to enjoy torture, when he talks about whipping, he means the real thing like the cat or maybe he'd even like the knout.
Obviously when Harry had to write 'lines' with a magical quill that caused the writing to be cut into the back of his hand, eventually resulting in bleeding, as a detention punishment imposed by Dolores Umbridge (in THE ORDER OF THE PHOENIX), that was a physical punishment although of course nothing like a spanking.
In THE SORCERER'S (or PHILOSOPHER'S) STONE, a detention punishment for Harry, Ron, Hermione and Draco Malfoy was to go into the Forbidden Forest at night to help Hagrid track down whatever was killing unicorns there--Harry and Draco were even split off (accompanied by Fang, who looked fearsome but was "a bleeding coward" according to Hagrid) on their own, which was clearly rather risky for first-year students (eleven-year-olds), I'm figuring.
Nobody got hurt, although Harry did come face-to-face with a unicorn, but I'm still thinking that a good bare-bottom switching from Professor McGonagall (who'd assigned the kids that detention) might have been more appropriate than a potentially life-threatening nightime sojourn into the Forbidden Forest.
Well, that's the 'wizarding world' for you--look how high-risk a sport quidditch is...

--C.K.